| In order to improve performance and increase service life of gas turbine blade,prepared(CrxAl1-x)N gradient coating on 2Cr10MoVNbN stainless steel through adjusting Al target power by closed-field unbalanced magnetron sputtering method.Coating microstructure and phase structure were examined by SEM,EDS and XRD.The thickness of coatings can be detected by ball crater and observed cross section by SEM.Hardness and elasticity modulus of coatings were determinated by nanoindentation and Vickershardness testing.According to DIN-Fachbericht39,adhesion strength can be obtained.Employed pin-on-disc machine to evaluate frictional wear performance.According to GB/T13303-91(Steels Determination Method of Oxidation Resistance),high temperature oxidation experiments of different(CrxAl1-x)N coatings were carried out at 800℃in air.The(CrxAl1-x)N coatings after oxidation experiments were analyzed by XRD,EDS and SEM.The results indicated that all the coatings were amorphous structure and with increasing of Al content,grain size became lager and integrated on surface.For the thin thickness of coatings,hardness should be detected by nanoindentation. With increasing of Al content,although coatings hardness decreased,it's intermediate zone became more smooth and wide and these characteristics can make substrate and coating had great compatibility.The Al:Cr atomic ratio of coating made by E method was 1:2.3.It has better adhesion strength and frictional wear performance for more Al content and amorphous structure of coating.The addition of Al,enhanced coating high temperature oxidation resistance.XRD found iron oxides on substrate after 2h oxidation;after 20h oxidation,coating made by E method still has smooth and metal luster surface condition and XRD found only chromic oxides and Aluminum Chromium on coating surface. Observed coating by SEM indicated that surface grain has small size and contain little oxygen.The coating made by E method has better high temperature oxidation resistance.
|
PDF Full Text Request